1. Field of the Invention
This invention pertains to construction tools generally, and more specifically to a tool for selectively elevating the head of a pneumatic nail gun above a nailing surface, thereby varying the penetration depth of a nail being driven into the nailing surface.
2. Description of the Background Art
Pneumatic nail guns have been in use for a number of years, primarily in the building trades, where applications require driving hundreds or thousands of nails per day. The pneumatic nail gun has resulted in the saving of time and energy required for driving the large numbers of nails typical in industrial applications.
It is often desirable when using a pneumatic nail gun to drive nails to varying depths, especially, for example, when the surface in which a nail is to be driven overlies a second surface which is easily damaged by nails, or else where the second surface is impervious to nails. Additionally, it may be desirable to be able to vary the penetration depth of a nail when a user wishes to tack an article to a surface, temporarily. A nail driven to a shallow depth more readily accomplishes these ends than a deeply driven nail.
In normal operation, a user places the end of a pneumatic nail gun head flush with the nailing surface. A pneumatically operated drive bit inside the nail gun drives the nail head flush with the end of the nail gun head and the nailing surface. The drive bit is operated by a trigger or like device to "fire" the nail gun.
Alternatively, safety awareness in recent years has regulated the mandatory addition of a safety device known as a "push lever". The push lever safety device generally includes a slidable safety head which partially surrounds the firing head of the nail, and further includes an arm extending outward from the safety head along the exterior surface of the firing head to communicate with a drive bit operating mechanism.
Prior to operation, the end of the push lever overlaps and extends beyond the outlet of the firing head of the nail gun. For single nailing, the user presses the push lever against the surface to be nailed and pulls the trigger of the nail gun. For continuous nailing, the use pulls the trigger first and then "bounces" the push lever along various points of the surface to be nailed. In either manner, at the point of firing the end of the push lever and the end of the firing head are substantially aligned and the push lever is in contact with the drive bit operating mechanism.
The addition of the push lever therefore requires the user to undergo a two-step procedure to fire a nail gun: (1) depress the trigger and (2) press the press the push lever against the nailing surface. The push lever therefore insures that the nail gun will only be fired when the firing head of the nail gun head contacts the surface to be nailed. Hence, a push lever equipped nail gun will never fire in mid-air, where a propelled nail could travel and cause unwanted damage or human injury.
In the past, when pneumatic nail guns were not equipped with push levers it was found that by elevating the end of the nail gun head above the nailing surface, the depth of penetration of a nail could be varied. Because this lead to instability of the nail gun and lack of control over the depth of penetration of the nail, fixed length spacer devices were developed for elevating the nail gun head above the nailing surface. Slidably adjustable spacers were also developed but required use of a wrench or screwdriver for adjustment.
Furthermore, prior devices have failed to provide a nail gun head elevating tool which adapts to push lever equipped nail guns. Given that regulations in many locations require that nail guns be equipped with push lever safety devices, a need exists for a nail gun head elevating tool which can be used with push lever equipped nail guns.
The present invention overcomes the deficiencies of the prior devices by eliminating the need for an additional tool, such as a wrench, to accomplish the function of varying nail penetration depth. Additionally, the present invention is specifically designed to adapt to any model of pneumatic nail gun head, whether equipped with a push lever safety device, or not.
The foregoing information reflects the state of the art of which the applicant is aware and is tendered with the view toward discharging applicant's acknowledged duty of candor in disclosing information which may be pertinent in the examination of this application. It is respectfully stipulated, however, that the information disclosed herein does not teach or render obvious either singly, or when considered in combination, applicant's claimed invention.